Memory cells of electronic memory devices such as dynamic random access memory typically employ a number of electronic components in order to save data. For instance, in order to store data, a combination of electronic components such as transistors, diodes, and/or capacitors are typically employed in such memory cells to store or not store electrical charges. If a charge is stored in such a memory cell, that may indicate a logic “1,” and if no charge is stored in such a memory cell that may indicate a logic “0.”
An alternative approach for storing data is to use memory cells made of phase change material (PCM). A PCM is a material that can be placed into at least two physical states, a crystalline state and an amorphous state, by increasing or decreasing temperature. By changing the physical state of the PCM material, certain characteristics of the material, such as electrical resistance, may also change. Such properties may be exploited in order to form memory cells made of PCM (herein “PCM cells”).
Such memory cells typically require additional components such as switches and heating elements in order to function as memory cells. The switches are used to drive the heating elements that provide the heat needed by the memory cells in order to change the physical state of the PCM in the memory cells. Unfortunately, because of the presence of these additional components, these memory devices tend to be rather large and they leave relatively large footprints on chip real estate. As a result, so far they have been of limited use as electronic memory devices.